Wiznet makers

Project Description

Arduino-based project that uses ESP32 and W5500 Ethernet modules to connect to an MQTT broker and post messages periodically.

1. Include libraries :
   • <SPI.h> : Library for SPI communication.
   • <Ethernet.h> : Library for Ethernet connectivity.
   • <PubSubClient.h> : Library for MQTT communication.
2. Define constants and variables :
   • ETHERNET_MAC : MAC address of the Ethernet module.
   • ETHERNET_IP : IP address to be used when connected via Ethernet.
   • ETHERNET_RESET_PIN, ETHERNET_CS_PIN : Pin numbers for Ethernet module-related pins.
   • MQTT_HOSTNAME, MQTT_PORT : MQTT broker host and port.
   • MQTT_PUBLISH_INTERVAL_MS : Interval for periodically publishing messages via MQTT (1 second).
3. Ethernet and MQTT client setup :
   • ethernetWizReset() : Resets the Ethernet module.
   • macCharArrayToBytes() : Converts a MAC address from a string to a byte array.
   • connectEthernet() : Configures and initializes the Ethernet connection.
   • setupMqtt() : Sets up and initializes the MQTT client.
   • connectToMqtt() : Connects to the MQTT broker and sets Last Will and Testament (LWT) properties.
4. setup() :
   • Serial communication is started.
   • Ethernet connection is configured.
   • MQTT client is configured and connected.
5. loop() :
   • If the MQTT client is not connected, it attempts to reconnect and waits until the connection is successful.
   • Handles MQTT client's loop processing.
   • Publishes the device's uptime to the "mydevice/uptime" topic at intervals defined by MQTT_PUBLISH_INTERVAL_MS.

This example demonstrates how to establish communication with an MQTT broker using an ESP32 and Ethernet module. It periodically publishes the device's uptime to the "mydevice/uptime" topic, making it a simple example for IoT device communication.